Wireless Communication Method and Terminal Device

This application is a continuation of International Application No. PCT/CN2023/078201, filed Feb. 24, 2023, the entire disclosure of which is incorporated herein by reference.

The disclosure relates to the field of communication technology, and in particular, to a wireless communication method and a terminal device.

Some communication systems, such as new radio (NR) systems, support sidelink relay from a terminal device to a network. During the sidelink relay from the terminal device to the network, the terminal device may need to perform multiple operations, such as relay discovery, relay selection, etc.

In terrestrial networks, the above operations are performed based on the measurement of signal quality, for example, the measurement of reference signal receiving power (RSRP). However, in non-terrestrial networks (NTNs), the signal quality of the NTN cell cannot accurately reflect the near-far effect, which results in that the measurement based on signal quality may no longer be applicable to NTN communication.

In a first aspect, a wireless communication method is provided. The method includes the following. A first terminal device performs a first operation when a first condition is met, where the first operation is related to a process of accessing a network device by the first terminal device through a first relay device. The first condition is associated with first location information and/or first time information. The first location information indicates location information of the first terminal device in a serving cell. The first time information indicates time information when the serving cell serves or stops serving the first terminal device.

In a second aspect, a wireless communication method is provided. The method includes the following. A first relay device performs a second operation when a second condition is met, where the second operation is related to a process of accessing a network device by a first terminal device through the first relay device. The second condition is associated with second location information. The second location information indicates location information of the first relay device in a serving cell.

In a third aspect, a terminal device is provided. The terminal device is a first terminal device and includes a memory configured to store computer programs, and a processor configured to execute the computer programs stored in the memory to cause the terminal device to: perform a first operation when a first condition is met, where the first operation is related to a process of accessing a network device by the first terminal device through a first relay device. The first condition is associated with first location information and/or first time information. The first location information indicates location information of the first terminal device in a serving cell. The first time information indicates time information when the serving cell serves or stops serving the first terminal device.

To facilitate understanding of the technical solutions of embodiments of the disclosure, a brief introduction to the related technologies of the disclosure is first given.

The technical solutions of embodiments of the disclosure are applicable to various communication systems, for example, a global system of mobile communication (GSM), a code division multiple access (CDMA) system, a wideband code division multiple access (WCDMA) system, a general packet radio service (GPRS) system, a long term evolution (LTE) system, an advanced LTE (LTE-A) system, a new radio (NR) system, an evolved system of the NR system, an LTE-based access to unlicensed spectrum (LTE-U) system, an NR-based access to unlicensed spectrum (NR-U) system, a non-terrestrial network (NTN) system, a universal mobile telecommunication system (UMTS), a wireless local area networks (WLAN), a wireless fidelity (Wi-Fi), a 5th-generation (5G) system, or other communication systems, for example, future communication systems, such as a 6th-generation (6G) mobile communication system, or a satellite communication system.

Generally speaking, a conventional communication system generally supports a limited number of connections and therefore is easy to implement. However, with development of communication technology, a mobile communication system will not only support conventional communication but also support, for example, device to device (D2D) communication, machine to machine (M2M) communication, machine type communication (MTC), and vehicle to vehicle (V2V) communication, or vehicle to everything (V2X) communications, and the like. Embodiments of the disclosure may also be applied to these communication systems.

A communication system in embodiments of the disclosure may be applied to a carrier aggregation (CA) scenario, a dual connectivity (DC) scenario, or a standalone (SA) network deployment scenario, such as a NR standalone deployment scenario.

The communication system in embodiments of the disclosure is applicable to an unlicensed spectrum, and an unlicensed spectrum may be regarded as a shared spectrum. Alternatively, the communication system in embodiments of the disclosure is applicable to a licensed spectrum, and a licensed spectrum may be regarded as a dedicated spectrum.

Embodiments of the disclosure are applicable to NTN systems and terrestrial network (TN) systems. By way of explanation rather than limitation, the NTN system includes an NR-based NTN system and an internet of things (IoT)-based NTN system. Exemplarily, in the scenario where narrowband internet of things (NB-IoT) and enhanced machine type communication (eMTC) access NTN, a system composed of IoT terminal devices and NTN networks can be understood as an IoT-based NTN system.

Embodiments of the disclosure have been described in connection with the network device and the terminal device. The terminal device may also be referred to as a user equipment (UE), an access terminal, a subscriber unit, a subscriber station, a mobile station (MS), a mobile terminal (MT), a remote station, a remote terminal, a mobile device, a user terminal, a terminal, a wireless communication device, a user agent, or a user apparatus.

In embodiments of the disclosure, the terminal device may be a station (ST) in a WLAN, a cellular radio telephone, a cordless telephone, a session initiation protocol (SIP) telephone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device with wireless communication functions, a computing device, other processing devices coupled with a wireless modem, an in-vehicle device, a wearable device, and a next-generation communication system, for example, a terminal device in an NR network, a terminal device in a future evolved public land mobile network (PLMN), etc.

In embodiments of the disclosure, the terminal device may refer to a device that provides voice and/or data connectivity to a user and may be configured to connect people, objects, and machines, such as a handheld device or vehicle-mounted device with a wireless connection function, etc. The terminal device in embodiments of the disclosure may be a mobile phone, a pad, a laptop computer, a handheld computer, a mobile internet device (MID), a wearable device, a virtual reality (VR) device, an augmented reality (AR) device, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical surgery, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, etc. Optionally, the terminal device may be configured to act as a base station. For example, the terminal device may act as a scheduling entity that provides sidelink signals between terminal devices in V2X or D2D, etc. For example, a cellular phone and a car communicate with each other using sidelink signals. The cellular phone and a smart home device communicate with each other without relaying the communication signal via a base station.

The network device in embodiments of the disclosure may be a device for communicating with the terminal device, and the network device may also be referred to as an access network device or a wireless access network device, e.g., the network device may be a base station. The network device in embodiments of the disclosure may refer to a radio access network (RAN) node (or device) that accesses the terminal device to the wireless network. The base station may broadly cover the following various names, or be replaced with the following names, such as, node B (NodeB), evolved NodeB (eNB), next generation NodeB (gNB), relay station, access point, transmitting and receiving point (TRP), transmitting point (TP), master station (MeNB), secondary station (SeNB), multi-standard radio (MSR) node, home base station, network controller, access node, wireless node, access point (AP), transmission node, transceiver node, base band unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), central unit (CU), distributed unit (DU), positioning node, etc. The base station may be a macro base station, a micro base station, a relay node, a donor node, or the like, or a combination thereof. The base station may also refer to a communication module, a modem or a chip configured to be set in the aforementioned device or apparatus. The base station may also be a mobile switching center, a device that performs the base station function in device-to-device (D2D), vehicle-to-everything (V2X), and machine-to-machine (M2M) communications, a network-side device in a 6G network, and a device that performs the base station function in future communication systems. The base stations may support networks of the same or different access technologies. The specific technology and specific device form adopted by the network device are not limited in embodiments of the disclosure.

Base stations may be fixed or mobile. For example, a helicopter or drone may be configured to act as a mobile base station, and one or more cells may move based on the location of the mobile base station. In other examples, a helicopter or drone may be configured to function as a device for communicating with another base station.

In some deployments, the network device in embodiments of the disclosure may refer to a CU or a DU, or the network device includes a CU and a DU. The gNB may also include an AAU.

The network device and the terminal device may be deployed on land, including indoors or outdoors, handheld or in-vehicle. The network device and the terminal device may also be deployed on the water. The network device and the terminal device may also be deployed in the air on aircraft, balloons and satellites. The scenario in which the network device and the terminal device are located is not limited in embodiments of the disclosure.

By way of explanation rather than limitation, in embodiments of the disclosure, the network device may be of mobility. For example, the network device may be a mobile device. In some embodiments of the disclosure, the network device may be a satellite or a balloon station. For example, the satellite may be a low earth orbit (LEO) satellite, a medium earth orbit (MEO) satellite, a geostationary earth orbit (GEO) satellite, a high elliptical orbit (HEO) satellite, etc. In some embodiments of the disclosure, the network device may also be a base station located on land, water, etc.

In embodiments of the disclosure, the network device can provide services for a cell, and the terminal device communicates with the network device through a transmission resource (for example, a frequency-domain resource or a spectrum resource) for the cell. The cell may be a cell corresponding to the network device (for example, a base station). The cell may correspond to a macro base station, and may correspond to a base station corresponding to a small cell. The small cell may include: a metro cell, a micro cell, a pico cell, a femto cell, and the like. These small cells are characterized by small coverage and low transmission power and are adapted to provide data transmission service with high-rate.

Exemplarily,is a schematic diagram of an architecture of a communication system provided in embodiments of the disclosure. As illustrated in, a communication systemmay include a network device, a terminal device, and a terminal device. The network devicemay provide communication coverage for a specific geographical area, and may communicate with a terminal device located in the coverage area. In some embodiments, the network device may be, for example, a satellite. The terminal deviceis located within the cell coverage of the network device. The terminal devicemay communicate with the network devicevia a Uu link (e.g., an uplink and a downlink). The terminal devicemay be located within the cell coverage of the network device, or may be located outside the cell coverage of the network device. In some embodiments, the terminal devicemay communicate with the network devicevia the terminal device. In this case, a sidelink connection exists between the terminal deviceand the terminal device. In some embodiments, in addition to communicating with the network devicevia the terminal device, the terminal devicecan also communicate with the network devicevia a Uu link.

It should be understood that, in embodiments of the disclosure, the terminal device refers in particular to a terminal device capable of sidelink communication. Terminal devices capable of sidelink communication can be classified into two types: relay devices (e.g., the terminal device) and remote devices (e.g., the terminal device).

The relay device may refer to a terminal device that supports providing relay services. For example, the relay devicemay provide relay services for the terminal device. In other words, the relay device has a relay function. Specifically, the relay devicemay receive uplink data from the terminal deviceand relay the uplink data to the network device, and may receive downlink data from the network device and relay the downlink data to the terminal device. The relay device may also be referred to as a relay terminal, a relay UE, etc., which is not limited in embodiments of the disclosure.

The remote device may refer to a terminal device that supports access to a network device through a relay service. The remote device may refer to a device outside the network coverage area or a device in an edge area of the network coverage area. The remote device may not be able to connect to the network device, or has a communication link with poor signal quality after connecting to the network device. The remote device may also be referred to as a remote terminal, remote UE, etc., which is not limited in embodiments of the disclosure.

exemplarily illustrates one network device and two terminal devices. In some embodiments of the disclosure, the communication systemmay also include multiple network devices, and there can be other numbers of terminal devices in a coverage area of each of the network devices. Embodiments of the disclosure are not limited in this regard.

It should be noted that,merely illustrates a system to which the disclosure is applicable by way of example. Of course, the method illustrated in embodiments of the disclosure may also be applicable to other systems, such as a 5G communication system, an LTE communication system, a NTN communication system, etc., which is not limited in embodiments of the disclosure.

In some embodiments of the disclosure, the wireless communication system illustrated inmay also include other network entities, such as a mobility management entity (MME), an access and mobility management function (AMF), etc., which is not limited in embodiments of the disclosure.

Currently, with people's pursuit of speed, latency, high-speed mobility, and energy efficiency, as well as diversity and complexity of services in future life, the 3rd generation partnership project (3GPP) international standard organization starts to develop 5G. Main application scenarios of 5G include enhanced mobile broadband (eMBB), ultra-reliable low latency communications (URLLC), and massive machine type communications (mMTC).

On the one hand, eMBB aims to provide a user with access to multimedia content, services, and data. The demand for eMBB is growing rapidly. In addition, since eMBB may be deployed in different scenarios, such as indoor, urban, or rural areas, its capabilities and requirements vary greatly. Therefore, applying a same standard to all is impractical, and a detailed analysis must be conducted with reference to a specific deployment scenario.

A key feature of URLLC is low latency. In an application scenario of URLLC, a connection latency may reach one millisecond or less, and a high-reliability connection in a case of high-speed movement may be supported. For example, during high-speed movement at a speed of 500 kilometers per hour, reliability may reach 99.999%. Typical applications of URLLC include industrial automation, electric power automation, remote medical operations (surgery), traffic safety guarantee, and the like.

Typical features of mMTC include high connection density, small data volume, delay-insensitive services, low costs, long service life of modules, and the like. Based on this, mMTC may include one or more of the following communications: communications of an industrial wireless sensor network, communications in a video surveillance scenario, and communications with a wearable device.

Currently, the protocol defines three RRC states of a terminal device: an RRC connected (RRC_CONNECTED) state, an RRC idle (RRC_IDLE) state, and an RRC inactive (RRC_INACTIVE) state.

The RRC connected state may be a state of the terminal device after completing a random access procedure but before performing an RRC release. An RRC connection exists between the terminal device and a network device, and a terminal device access stratum (AS) context exists in the network device and the terminal device. In the RRC connected state, data transmission, such as downlink data transmission and/or uplink data transmission, can be performed between the terminal device and the network device. Alternatively, transmission of a data channel and/or control channel specific to the terminal device can be performed between the terminal device and the network device, to transmit specific information or unicast information of the terminal device.

In the RRC connected state, the network device can determine cell-level location information of the terminal device; that is, the network device can determine a cell to which the terminal device belongs. In addition, the mobility management of the terminal device in the RRC connected state may be controlled by the network device. That is, the mobility of the terminal device in the RRC connected state is a mobility controlled by the network device.

The RRC idle state is a state of the terminal device when the terminal device camps on a cell but does not perform random access. The terminal device usually enters the RRC idle state after being powered on or after an RRC release. In the RRC idle state, there is no RRC connection between the terminal device and the network device, the network device does not store a AS context of the terminal device, and no connection is established for the terminal device between the network device and a core network. If the terminal device needs to enter the RRC connected state from the RRC idle state, it is required to initiate an RRC connection establishment process.

In the RRC idle state, the core network (CN) may transmit a paging message to the terminal device; that is, a paging process may be triggered by the CN. Optionally, a paging area may also be configured by the CN. The mobility management of the terminal device in the RRC idle state includes cell selection/cell reselection based on the terminal device.

The RRC inactive state is a new RRC state defined to reduce air interface signalling, quickly restore wireless connections, and quickly restore data services. The RRC inactive state is a state between the RRC connected state and the RRC idle state (that is, the RRC inactive state is different from the RRC connected state and the RRC idle state). The terminal device has previously entered the RRC connected state and then released the RRC connection with the network device, but the network device has stored the AS context of the terminal device. In addition, the connection established for the terminal device between the network device and the core network has not been released. In other words, a user plane bearer and a control plane bearer between the RAN and the CN are still maintained; that is, there is a CN-NR connection.

In the RRC inactive state, the RAN may transmit a paging message to the terminal device; that is, a paging process may be triggered by the RAN. An RAN-based paging area is managed by the RAN, and a location of the terminal device that can be learned by the network device is at the level of the RAN-based paging area. The mobility management of the terminal device in the RRC inactive state includes cell selection/cell reselection based on the terminal device.

Currently, non-terrestrial network (NTN) technologies are studied by the 3rd generation partnership project (3GPP). NTN generally provides communication services to terrestrial users through satellite communication. Compared with terrestrial communication networks, for example, terrestrial cellular network communication, the satellite communication has many unique advantages.

First, the satellite communication is not constrained by areas of the users. For example, the terrestrial communication network is generally not able to cover areas where network devices cannot be set up, such as oceans, mountains, and deserts. Alternatively, the terrestrial communication network is not able to cover sparsely populated areas. In contrast, for the satellite communication, one satellite can cover a large ground area, and the satellite can orbit the earth, therefore, in theory, every corner on the earth can be covered by the satellite communication network.

Second, the satellite communication has high social value. Remote mountainous areas, poor and backward countries or regions can be covered for satellite communication at a low cost, so that people in these areas can enjoy advanced voice communication and mobile internet technologies. From this perspective, satellite communication is conducive to narrowing a digital gap with developed areas and promoting the development of these areas.

Third, a satellite has a long communication distance, and a communication cost thereof does not increase greatly with the increase of the communication distance.

Finally, the satellite communication has high stability and is not effected by natural disasters.

Communication satellites can be classified into LEO satellites, MEO satellites, GEO satellites, HEO satellites according to different orbital altitudes, and the like. Currently, the LEO satellite and the GEO satellite are mainly studied.

The orbital altitude of the LEO satellite is generally in the range of 500 km to 1500 km. Accordingly, an orbital period of the LEO satellite is about 1.5 hours to 2 hours. For the LEO satellite, signal propagation delay of single-hop communication between users is generally less than 20 ms. A maximum visibility time corresponding to the LEO satellite is about 20 minutes. The LEO satellite has advantages of short signal propagation distance, low link loss, and low transmission power requirements for a terminal device.

The orbital altitude of the GEO satellite is about 35786 km. A rotation period around the earth of the GEO satellite is 24 hours. For the GEO satellite, signal propagation delay of single-hop communication between users is generally about 250 ms.

In order to ensure the coverage of the satellite and increase the system capacity of the entire satellite communication system, the satellite usually uses multi-beams to cover the ground area. Therefore, one satellite can provide dozens of or even hundreds of beams for ground area coverage, and one beam of the satellite can cover a ground area with a diameter of tens to hundreds of kilometers.

Currently, the NTN system can include the NR NTN system and the IoT NTN system.